How to grow sweet potatoes

Grab one sweet potato, two toothpicks and a jar or a water tight container that the potato can stand upright in without tipping over.
The toothpicks will serve as a platform so that the roots have room to develop.
Very Carefully push one toothpick all the way through the sweet potato about half way down .
Do the same with the other toothpick and therefore making a(+)with the toothpicks if looking down on the sweet potato vertically.

Place your newly punctured sweet potato in the jar so that all four toothpick ends rest on the rim of the jar
Fill the jar with water and set it in a sunny window. Make sure the jar stays full. In a few weeks purple eyes will start to emerge from the top and white roots from the bottom. Soon after, the eyes will sprout leaves.
Each eye will grow into a slip. When a vine from an eye grows to six inches pinch it off where green meets purple and another slip will grow in its place.
Plant the slips in your garden in loose fertile soil during the summer planting season.
Sweet potatoes require a long hot growing season. potatoes should be ready to harvest in about 120 days.

Plantation Site:
The most challenging step in growing sweet potatoes is selecting a plantation site that meets the growth requirements of this tropical crop. They grow best in well-drained sandy soils and in areas that receive full sun. Other ideal conditions for growing sweet potatoes are warm nights, moderate rainfall (at least 500 - 750 mm annually), slightly acidic soil (pH 5 - 6.5) and a long growing period.

Soil Preparation:
Mix garden soil with farmyard compost and sand (if necessary) to make it fertile and to ensure proper drainage. Sweet potatoes cannot tolerate extreme cold climates and frost. Considering these, the ideal time to prepare soil is 3 - 4 weeks or one month before the arrival of heavy frost. This way, you can grow sweet potatoes immediately after frosting is over and when the soil temperature measures approximately 70°F.

Planting Sweet Potatoes:
Sweet potatoes are propagated from tubers and/or slips (vine cuttings). You can bury sweet potatoes halfway in soil or water to promote slip formation. When the slips are about 6 - 8 inch long, gently cut them by using a sharp scalpel or knife.
Place the slips in the soil (½ an inch deep) in a slanting position, maintaining a space of about 12 - 18 inch between two plants.
Plant slips as soon as you cut them from the mother sweet potato tuber.

Growing Indoors:
In case you are looking for information on how to grow sweet potatoes in containers or how to grow sweet potatoes indoors, follow the same tips mentioned above to prepare soil and promote slip formation.
And instead of growing a sweet potato slip in garden soil, plant it in a large container (having potting soil) and place it in a sun-lit garden area or a sunny window (indoor gardening). Know more on container gardening.
http://www.buzzle.com/articles/container-gardening/

After Plantation Care:
After care of sweet potatoes mainly involves regular irrigation of the plants, especially when they are in the tuber formation stage. A very dry soil (drought) results in small sized tubers, whereas a water-logged soil causes rotting of the sweet potato tubers. In short, you can keep the soil moist, but not wet. Also, keep an eye over weed growth and diseases like root-knot nematodes and wireworms